A hydraulic excavator includes an undercarriage having a crawler, and a rotating superstructure supported in a rotatable manner above the undercarriage. An engine, a hydraulic drive device, a fuel tank, a cooling unit and the like are mounted on the rotating superstructure, and furthermore a counterweight is mounted on the rear portion of the rotating superstructure.
Japanese Patent Laid-open No. 2009-179960 describes a fuel tank, a fuel pump, and a fuel line and the like previously assembled in a support member as a fuel system sub-assembly in order to improve assembly workability. Accordingly, assembly workability is improved by mounting the assembled fuel system sub-assembly as one component in the rotating frame.
In Japanese Patent Laid-open No. 2005-68962, a fuel line structure in a hydraulic excavator is described that suppresses strength reduction in a side plate that constitutes a rotating frame and improves fuel line installation workability. Specifically, in the Japanese Patent Laid-open No. 2005-68962, the rotating frame is constituted mainly by an I-type steel and the fuel line is installed near the end portions of a pair of side plates along an outer edge portion of the rotating frame, and further the fuel line straddles one of the side plates and is installed along an upper edge of an end plate.